SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b13f4ea0a4a03c061910ba008dfbf2f07a4ee8ff7ee6e2bccb326eb99b13db2d' 
  AND token = 'WQXJPCVDFpg/x0pFMY0AEmOWOvNrqD+oxNBqm5mMdyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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