SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d47d6b8f1c4a4263feea1279bec2b65b351cbbaccf51edb8216506ac598cea' 
  AND token = 'MhGG/nCQKL/UrvwL43GvfIsY94y7QnoXyx2I4+lMsSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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