SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbc059495d4063fa614e351ac468f8a63a0be14078ca93dbd4b2f296ea0a1013' 
  AND token = 'g+5uagso99qgjd76ZumVvY5qsY4CNwz7tKfxKlWyrcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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