SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96d12ab0e3edde61f4b19d8a73e1b50697a2407adbc7099301ccddcc3bfb3826' 
  AND token = 'WOmGNGBQRm6+9zExD29bAcyLdyJCCdO0jBbZfR1okIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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