SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8539c389e224e9c8049a0e1648a85ab58ea5fa2a343a20eaecd7e13fee58ec32' 
  AND token = 'o5YzQ84rCBRRqLSRYHwBI4WGvq6yG5H/spmXGgSrWQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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