SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e5ce5d1881a1eff629555071af3fa53c9bfc54ee3a42413d0b7449a5892a6c6' 
  AND token = '5ggip8T9FUgsqy+gFYbHw84+l3GR3AGD3pEU63H2l7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}