SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '137cc3cc4403832ec198b5429fdc2224edbb95b10de72497a3ca2d1e1d90526b' 
  AND token = 'UMVYy3R0rVbSOBs1vUtPAB6RvLPVjuerXnSYodzcZGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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