SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4d486ecc4b2c88282142b7b256af2c00e75f4286bfe20f9f5ffe3978215191e' 
  AND token = 'HcDwllR4Fp7+3Y+dWgCJOZw6h+mqw295+s3xp2NiTR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}