SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2503a710bdbe174bf03f2a401983325a86d82d0f62f6d2d4b5670ae21340035d' 
  AND token = 'Vlwzzerwrhzng3+b+nPWedNmMUdoausdZknFx3EmGA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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