SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '882dc395067e3037ac45d96fa25b022f47897e071cc22388985f4915b1c33537' 
  AND token = 'R0rVnUCdrbfqBzDtHMVMclmXcSUvEQAU/Y71Z7btiYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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