SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5364126e5d5ba7f0945a30f28f1bf561aad423fd9289e191e5942cb888ef2f76' 
  AND token = 'Oc5i9d4fFdg/JaAiXxwgBG6ZUOwR/AGBEad69G3nGAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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