SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd42650634c7b3ddc72fdf1a777a0a13c89a0b331e1571ceadc4cf22c0a85d7e' 
  AND token = 'yNq1UFsbpg3FSoDgYsdHLt9fO6v4DEaEzenGuSnmgus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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