SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36ac793b98509fd091fd3ee5ec88423ca48a7a3c520f65fbbad11798d39ae2d5' 
  AND token = 'ho36pindvgtABweWdep/CXhDduaOPrCHjIWETg/w/s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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