SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98e2e8d0d9763839cde791a9fa01f854001daa54b3229331b11da75bef7aa38c' 
  AND token = 'ZqcidbZ7GrTnuI/A4n9tVLpvUPy10h8BxJcMKp113e4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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