SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c25e0ec8e60a2fa7c42c3d26b8739d8d695456b71c065534233bd1073af82a5' 
  AND token = '4ZQAUqGMpG+yEt6P0L8XTpOvgpmCKVojTkefSIL/ev4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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