SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac13a4642ba81b71417a04bce470ae898fa11bf60a1c0a617e1f802f8d7bc749' 
  AND token = '7aHwpRLm1+68e6vVGmM4q/O3fAmQL1623z0uUUmBMuI=' 
  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"
    }
  }
}