SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2e7c4d7babe1477094b4eaac9895b40ad879c604a6a9bc50e70060fafc8b1f1' 
  AND token = 'b2ebKSz7tdeNWESnYPWTMLJ/PC3EVTNOGabaE/gofz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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