SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98e5f62307bf61e4c25b67f27264646e2b3c9b479d1feaf5b75a39f7a797eed2' 
  AND token = 'Fnu2LzbP8w/bbkpUwNDCJZqqs0MCrLtX7zAng0XrSjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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