SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f11613b3e3190eb6efdb6e202a771be8f92daca9f5c1d0f4232a71660638d059' 
  AND token = '1pcd+D2gKiZ1QcmFdcLHkeRN6d3ih0OxcggJBXO73ZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}