SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4383a3963b11b2b687d2c3d79e51bfa6b930bc5624209d766bcbf58452f2ec2e' 
  AND token = '33qRG/kIj76lgPQChLruYQEZNW7Kx1QrccUlIUBrDFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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