SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55bad17a32c8796662ffbde07799caa5cb30ac3d50d64d31c5d8c89cd5a9dd0b' 
  AND token = 'FzYlqnTXZ2wLu8iuj1Oo/HVlvl4my3UYeK+F3siB4V0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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