SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a4e939cf217d7898421dc87b8faab895327616c3fda3d1bd8597d65abcede7' 
  AND token = 'KqU+lQZuE3jIlOD26HyPrbTb9iWR2S9DOADwYDOAQQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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