SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdd7dfd0c89cf318a5069cb02deeb310127ef6d089079ab696805a16dcec0e2d' 
  AND token = 'mA4Y4o79ZRPlHsn0PKEmpTtInlbcN55cKRrB7qt1orc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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