SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b86c0990c069fbb7a08453294c740d6c1a365655025de77580e0c1123ac9f47d' 
  AND token = 'WdUw+NvBts8yo/Pk1fX1viEENWOjtPQq/F2vV0chm6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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