SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66b97d602151053e04536e8781bd6e9776cb5d97a951c15037eb87ceebc0cd5b' 
  AND token = 'VmIFDFwf/KdzHMaEYC8J1sPR/fXU3OIMdbcoVyZNU4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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