SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ef5a249a82961cc6c1d0e8079ba0b28cb7832f9ccc0a3310c7d893a4f627efe2' 
  AND token = 'iHh+v9mpOw58Cadh6erNDLkg+qG4vj5n4+QniWKXBfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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