SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '4bf181bed2ce160d8fadd8324434754e2484f4fa9ae632fa192443598d4a708f' 
  AND token = 'hTAU9jc9wFAm/VSR0z1vHp7a2D+nshH7/K+AjLe37uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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