SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2281e2043229a471298795a26fc616e0e1f178c06c27aa88e5086e4807042048' 
  AND token = 'kcJ1rqSCu1WX7FkAuImgS2B8hSHecPjCJ860XHXsHmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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