SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '68a4b9277db0e906d230d671d954741eb9587eb25e1f32edaebb3d92f2656759' 
  AND token = 'SS98yGKL2dm/92fDhKYG2hs4I0ZIohUKpAXuan2gDhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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