SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0debf80606d1739cf3f76cc17eb76421758ff3c412150d010af37298c7b9d9e' 
  AND token = 'IFhC5JNV000+mNEfTogYkdTpN3t5jqOryOju8PJxeKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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