SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e136cfbfd31865585f3d84705369ba2f25783c7b851c47b0467e1ef8a0c44bf0' 
  AND token = 'IbTmiwUCOHL9YcTeVN/0gXpbt1dwcTXYVMsiz8idbHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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