SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f9ad2bbb4dc261873394f570affc25e58bcea51653ab02c3e672e4da41020b01' 
  AND token = 'zJwWFtMyZza3Gat/CsU8tctDhibbtSuvXVBfi6DdlSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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