SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f780edc4db8a7bd31432844263a8661f207323192dea321261e3b4f79a1c2993' 
  AND token = 'RkhGJMAqkXqxZjb6xxn+3TS+WGxGVFBMGuqSrlhigFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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