SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7990280b66a2475a5ecf0b1f3a4ec60b4e6874692b9ffdf273b7c9c2bd51518a' 
  AND token = 'Dnh5ihx3eg6Qwxk8g5OtYZLIKWPgv4Gzi84qYQ3DUS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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