SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d3fae71f84293ba497aaeea60d6fb31fbb5a46b76a33f9533b5d32a95244ba9' 
  AND token = 'dy0JJX2H9Xs9UF156YX7B2uZbg/L+wGMBqkJ8vCPDfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00102

JSON explain

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