SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c410af40ea50617f3ad5b2f2a976fb5c8279fc263e998b0eedd52249685da39b' 
  AND token = 'yRj1IsYY5csrFYNYSsQBSao8gtLqs2YGfIvmTsI4sHM=' 
  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"
    }
  }
}