SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec0ac04bb2caa306d3dfe4ed0341bc056b4212845e426528a9300c62fbcf1765' 
  AND token = 'pmo6kr70S8QnsouwThMfkEbTwZ0d8T5l9Gmg1stAsQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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