SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46a87395a1d311fffed019a7cf21857c3aeabeb9b4b3adc1bd03399e5571823d' 
  AND token = 'cjDNacsLZvDnYhxveBT37KmBvX361rmOv8N9AN7dj9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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