SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c614617ff16323c78e5be3e0e668e84d52efd9c22fcc767b26d322b245384f6' 
  AND token = 'h8RakPtm5LZMlhw592hxv/6/BnRMdWdgSK8LfJvgRuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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