SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97efaf66e0eaf770389275b11f14fac325ed59146e3d3d4dabf053614f3f8ea1' 
  AND token = 'AzBW9onzY48oAvYmuOsREjB+ExFfo0Y37Z+dic1m9gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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