SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f55662b59d6a29255bc9ef667c1f596a2f68915066a13845a5afe7bdc4daa4d2' 
  AND token = 'D5letWIS29BlCHhEGrOspYGXsVCW+whjgfHy8vnfNwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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