SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fac92592efc01bca5ff004a5fa1a8cb68afd9698bf7e9e37350f7a9faec9960' 
  AND token = 'VMGOwyl0vg8EqyO0UVfcS068sk2zFnug3zbAhW/q/LQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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