SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92a0f1f1236f1422cee04006418249dfaf91c2ba578404e6cf877ae3422ac702' 
  AND token = 'GqXZlZx2fJwl57vDYs+nUqJMI2vAZjz3FP+wG3Wm/sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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