SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc7dc0bec38e3a5702302077c8f5d849e44615e57cacadc826a8ba78b757f23a' 
  AND token = 'JAKCyRYDzqwPC6Tl9q3v8aNKxQeCWLAcmZfA07K0Npw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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