SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a59edea4910e71cd37eae05bf0926d61f8f953b620087745faf365f3aabc25c0' 
  AND token = 'OgsGVh1MIrDRqOFhlxMsm5KD3g+iJbpcNa+5YkGaiAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}