SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd2669cb865d1adce373feffcf0c18f12aa1ac43087b6cc419bae907f8c523ae' 
  AND token = 'y1r8ylnTEdMI10rDy0NdGiv8qFiec0h3aRuREIwLdlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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