SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9123f3e5a7f5bae5ef42c2d80acbf3e423f4472ab898ca82d0d45547f52ec44' 
  AND token = 'rIFbTy0YeYnaRJwuSh4fXBjBfEb643WBfhOVcbidWyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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