SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efbc546a1e52947c83e32bf805b2bdb46659368f1e87f6f250e435ffd534ef3a' 
  AND token = 'mxVq7xZ1oQ3PB8h/L6w8WezkNcGfMuCIb0cwu9ANCJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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