SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74674d71db1cb171c2ac93624f12988d050b8ee2e6ce078fc5bd8bdb55dfe4a9' 
  AND token = 'Bzj0E/6PzlIHXt+1g5gpRuOi4+CRRwDp3ISicekwx0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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