SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e3e435b69d22da7a67a180e9d306ba9b4c4b9ed76a85a15c8bf5abbc349837e' 
  AND token = 'TRTEjcN40tVCpye1xfFGeFYbpa0ay7JnkdMlfl/c/18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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