SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cfa849ad4f8c08756b634b3e5539d9ee11a11bccc77ac80dda282da8aa610575' 
  AND token = 'HLr0m4if2ZKZo4rEOzZM2+BbjmRpXiw54Yjm5lq/EJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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