SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16215335f0db3231463312745934f698d8809edd89b74fe59b54cda34a92b0eb' 
  AND token = 'RzqGyAI5BrrUvoir2Bklxpu2fdSFk1u4RN85MR6Nn+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}