SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c5a11381cf2e01bab3e701bedfc3619be0f9f7cf9d4b4b3281c5f8b730a5bef' 
  AND token = 'kV2yda0e1F82YA1Mob4jbZt53W5Q5lTYB9s5JdH9rvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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