SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ff941dd25f16490791803275027b70956067c12c848698f011524211643a9f0' 
  AND token = 'qKVG75mNolwh+iDYn1SVp+LjfIVtU6rkvSZb0ajuppg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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