SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b796aedd62f16fce4f6339c92ae816660802faaee9d6b9a8cd516b38fca4041' 
  AND token = '609I2CSckKydVGtL3SYM0bIzvn+FkavLG2htR5DhWAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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