SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c9f2a905bbfb156304008b39eb7d7d7bee7f16bd52d7af42fd583e1d490b2e' 
  AND token = 'EyNQDvELtZfaQkOduJQGDZaGwSg4Hf14JLLTY0zWf0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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