SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dadceac1e3e89abf08ef222bda62f00465101156311ce6352acaa00421615e5' 
  AND token = 'sMt9TvmIjI4E4AimbDQJDM3RXYRnosbKdECTEAGn5gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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