SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2e89da8d54d9a22f0f018adb382b7e48f8c5964436741983ec738562f0d729e' 
  AND token = 'aLZJ9OX2wue0RlX8t828RcwXujWKylIdUfEU2194PiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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