SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fea366cad4bbe47d0011d202aedf1e1c51cd4a0c5ebe4d1ce9ab24f960a0e85' 
  AND token = 'EIzFol6RYuqDSsbTK07tj09zcbU/OIRbegjuBv56BYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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