SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c86cb5546b0b47456ee22d0543c39d954d93b48526a1f2752595f2f817827ac' 
  AND token = 'iA5LBMzbYCiKsJ6JEqng8DiZWe7aKUmh4NuPUPuVxK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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