Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b20c1b5a539f500fc09a8ecb8bbe5e2adc47a4986d3aae5275d83520a3bedafa' 
  AND token = 'ikzi+Pm7ZKpamjQ6yFOst2PV2908X4ftCgnxFGuO+GE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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