SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ee067a1c06683ba36757d8441ecff0bfba94c88d0a31598e345d47fede431cf' 
  AND token = 'RTpjsCGKEFT8tftnkxTfAgjGlGWKyUCj/+Em7AIEbvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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