SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b17a9b42993df4c3d59bacd22750c8fd8a88f932702b255d5d8b26500d58107' 
  AND token = 'paPPZFzsdVx23cAgYAHbTCpI3Gi77VtikSXNLwekdAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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