SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36de1ff23d17af94e8267fb4a31c641a53c4505fe9e2658182b3ad291a56066d' 
  AND token = 'dfuCc5BGYfL4bCFFejP508vRprUJJRAkeZjIFtV3tik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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