SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cccdcfccce27bb3a49c12378321e80693c2959ccea6005926c7660e0a43305bd' 
  AND token = 'FiFKpaDSkJ8WTQQBZ5G4975k84iddonrqe6AscsTY7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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