SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '513ccfdff242010d3101c040639457b002685e3ab8960f8e29cbd1acd7a90ed8' 
  AND token = 'Yy6iGfYbaobS9fVmRrkuunDgDNnb87Y4Yr2Ur4AaF3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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