SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38d3f03d85b9dead34c1be35d1b3af94371d36ad2bfd6e20a76666a26af924c0' 
  AND token = 'N4IpEy4kGWCO3Dgu5o1uLDar3IXPmS6W5AVprjVRXb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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