SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '408d4d7fa9a37f06a2640ad497210b360012807b813e9805eba2fd120f503069' 
  AND token = 'A5v1lH27jtG0Rn/nBRV2VgxV3uONv5DoUEPXIHZ7l60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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