SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47fbf230cf275cff31a14e9ec4ec500bfa1ca7bf5c3a8980c7c8f5fc03879fae' 
  AND token = 'ICTBSQSH9KEdMXJ0/IBadWDM1UF18/owideJ2jdmBpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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