SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7ddc0f5222340b9e40791837470faf3d880b6459ccfdb89c0f3a72853b365c9' 
  AND token = 'qMDTGWD4NsYubCfRRXOB0w/jTPQtvMv/VxiS2hd6uEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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