SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bd9c4f4fedece7a63742c496e9c5c59622dd4f6a0a3f88febfca1b2e9afc8c8' 
  AND token = 'RWWEN/3VlqZ6zYjhu53rxLAww2CNIOWgdPVGLW3JwXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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